William j



(No Model.)

W. J. JOHNSON. I

Machine Trimming St ereotyp Plates. No. 231,427.v PatentedAug. 2 1880.

lllllllmllllllhl lllllllllllllllHlHillllN N. PETERS, PHOTD-LITHQGRAFHEH, WASHINGION. D c.

UNITED STATES PATENT OFFICEQ \VILLIAM J. JOHNSON, OF BOSTON, MASSACHUSETTS,

MACHINE FOR TRlMMlNG STEREOTYPE-PLATESf SPECIFICATION forming part of Letters Patent No. 231,427, dated August 24, 1880.

Application filed March 29, 1880. (No model.) I

To all whom it may concern Be it known that I, WILLIAM J. J OI-INSON, of Boston, in the county of Suffolk, State of Massachusetts, have invented a certain new and useful Improvement in Machines for Trimming Stereotype-Plates, of which the following is a description sufficiently full, clear, and exact to enable any one skilled in the art or science to which my invention appertains to make and use the same, reference being had to the accompanying drawingsflbrming a part of this specification, in whieh- Figure 1 is a front or side elevation of the machine, and Fig. 2 a vertical transverse section of thebed and holder or strap with the plate in position on the bed.

Like letters indicate corresponding parts in the different figures of the drawings.

My invention relates to that class of machines which are employed in trimming the curved stereotype-plates used on rotary or cylinder printing-presses; and it consists in a novel construction and arrangement of parts, as hereinafter fully set forth and claimed, by which a more effective device of this character is produced than is now in ordinary use.

In the drawings, A represents the frame; B, the treadle; G, the bed, and D the strap or plate-holder. The bed is arranged and secured horizontally in the upper portion of the frame,

being curved or formed to correspond with the plate to be trin1med,and provided with a groove, a, near each of its ends.

The strap or holder D is preferably com posed of leather, and has one'of its ends attached to the bars at d, which are secured to the, under side of the bcd O, its other end being provided with the hook i, for connecting it with the treadle B.

A horizontal shaft, E, provided with the gear G and pulley H, is disposed in the upper part of the frame A, passing through the bed 0, and mounted on this shaft there is a swinging or movable frame or cutter-head consisting of the arms J J and bar K.

Journaled in the frame J K, parallel with the shaft E, as seen in Fig. 1, there is a shaft, L, provided with the circular or rotary cutters ters are formed to correspond to the bevel it is desired to give the edges of the plate N, and are of such size as to extend slightly into the grooves a a, as shown, thus enabling them to cut entirely through the plate in performing their Work.

In the use of my improvement the frame J K is swung or pushed into such a position at the rear of the machine as to prevent it from interfering with the insertion of the plate. The strap D is then thrown back and the plate N placed on the bed, as seen in Fig. 2, after \vhich the strap is brought forward over the plate and attached to the treadle by the hook v the treadle being then pressed down by the .foot of the workman, thus securing the plate firmly on the bed. Power is now applied through the belt M and pulley H, the frame J K being swung or pulled by the handle 1? to the front of the machine and moved back and forth over the bed until the rotating cutters m or have out off or properly trimmed the ends of the plate.

The arms J extend below the shaft E, and are provided with aspring, h, to render the frame J K more easily manipulated; but this may be dispensed with, if desired. I

It will be understood that the bed O is the segment of a cylinder whose longitudinal axial line is coincident with the axial line of the shaft E, and. that the cutter-shaft L describes the arc of a circle whose axial line also corresponds to that of the bed.

It will also be obvious that the shaft E and gears G 2 may be omitted, if desired, without departing from the spirit of my invention, in

- which case the arms J J are pivoted to the sides of the frame and the pulley H mounted on the shaft L in place of the gear 2, the belt M being controlled by proper tension mechanism to prevent it from slipping.

The plate N may also be confined on the bed 0 by other means than the strap D and treadle B, though I consider these appliances preferable, the strap not being liable to injure the casting, and the treadle enabling the plate to be secured readily and firmly and shaft E, provided with the gear G, the curved 10 to be released Without difliculty after being bed 0, provided With the grooves a, a, the

trimmed. strap D, and treadle 13, substantially as speci- Having thus explained my invention, what fled. 5 I claim is 7 WILLIAM J. JOHNSON;

In a machine for trimming curved stereotype-plates, the swinging frame J J K, carry- Witnesses: ing the rotary shaft L, provided with the cut- 0. A. SHAW, ters mm and gear 2:, in combination with the E. E. BRADBURY.

t v \l 

